A050491 a(n) = C(n)*(12n+1) where C(n) = Catalan numbers (A000108).

1, 13, 50, 185, 686, 2562, 9636, 36465, 138710, 529958, 2032316, 7818538, 30161740, 116635300, 451980360, 1754766945, 6824030310, 26577181950, 103647597900, 404703270510, 1581953021220, 6189965556060, 24242879364600, 95027512981050, 372782298576636, 1463445866837052

Offset

0,2

References

Albert H. Beiler, Recreations in the Theory of Numbers, Dover, N.Y., 1964, pp. 194-196.

Links

Andrew Howroyd, Table of n, a(n) for n = 0..200

Formula

G.f.: (11 - 20*x - 11*sqrt(1 - 4*x))/(2*x*sqrt(1 - 4*x)). - Amiram Eldar, Jul 08 2023

Mathematica

Table[CatalanNumber[n] * (12*n + 1), {n, 0, 25}] (* Amiram Eldar, Jul 08 2023 *)

Prog

(Magma) [Catalan(n)*(12*n+1):n in [0..25] ]; // Marius A. Burtea, Jan 05 2020

Crossrefs

Column k=12 of A330965.

Cf. A017401, A027810, A000108.

Sequence in context: A050410 A121991 A121990 * A332589 A022283 A135971

Adjacent sequences: A050488 A050489 A050490 * A050492 A050493 A050494

Keyword

easy,nonn

Author

Barry E. Williams, Dec 27 1999

Extensions

Terms a(21) and beyond from Andrew Howroyd, Jan 05 2020

Status

approved